The invention relates generally to vehicles, and more particularly to wheel mounting assemblies for such vehicles.
Present day automotive vehicles typically employ wheel mounting assemblies utilizing a hub to which the wheel and tire of the vehicle are secured by means of several threaded bolts, often referred to as xe2x80x9cstudsxe2x80x9d or xe2x80x9clugs,xe2x80x9d which extend from the hub. These bolts are usually configured in a circular arrangement and extend through bolt holes formed in the wheel. A threaded nut or xe2x80x9clug nut,xe2x80x9d which threads onto each bolt, is then used to fasten the wheel onto the hub. There are different variations of such mounting assemblies. The two most common mounting systems are the stud-piloted and hub-piloted mounting systems.
In a stud-piloted mounting assembly, the bolt holes formed in the wheel for receiving the studs are usually chamfered or beveled at their openings. Likewise, the lug nuts used for such mounting systems are also usually chamfered or beveled to provide a generally frusto-conical shape that generally corresponds to the chamfered or beveled area of the bolt hole. Thus, when the lug nuts are tightened onto the stud to secure the wheel in place, the chamfered or beveled portion of the lug nut extends into and seats against the corresponding chamfered portion of the bolt hole of the wheel. The studs are arranged so that when the wheel is mounted and the lug nuts are tightened, the studs are centered within each bolt hole to facilitate aligning and centering of the wheel on the hub.
One of the problems associated with the stud-piloted mounting assemblies, however, is that the studs and nuts are subjected to very high loads and stresses, and thus subject to failure.
In hub-piloted mounting assemblies, the wheel is aligned or centered on the hub itself. The hub is provided with hub pilots or guide members to facilitate centering the wheel on the hub. The bolt holes of the wheel and the lug nuts of hub-piloted mounting assemblies are not chamfered or beveled, as in the stud-piloted mounting systems. Instead, the lug nut is usually provided with a flat-faced flange or washer portion which abuts against the face of the wheel immediately surrounding the bolt hole. The hub-piloted design eliminates much of the stresses placed on the studs and lug nuts that are encountered in stud-piloted mounting systems. The hub-piloted wheel mounting assemblies are often found on trucks, trailers and the like used for hauling large or heavy loads.
Brake drums may be employed with some wheels and incorporated into the mounting assemblies. In the hub-piloted assembly employing a brake drum, the drum is mounted over the hub. Lug holes or apertures are provided in the drum to allow the passage of the lugs or bolts therethrough. In most cases, the apertures have a diameter that is much greater than the diameter of the lugs or bolts. The wheel of such mounting assemblies incorporating a brake drum is mounted over the brake drum and hub and secured in place by lug nuts. When the lug nuts are tightened, the brake drum and wheel are secured and held in place against the hub.
In hub-piloted mounting assemblies, it is not uncommon for the drum to slip or shift with respect to the hub after the wheel has been mounted. This slippage is due to the oversized apertures of the hub-piloted mounting assemblies that accommodate the lugs. The drum is prevented from shifting only by the frictional forces between the interfacing hub and drum. Even when the lug nuts are fully tightened, slippage of the drum may occur. Tightening the lug nuts may further increase these frictional forces to facilitate holding the drum in place, but over tightening of the lug nuts beyond specification may result in failure of the threaded lug nut or lug or both. Further, the large forces often encountered by vehicles while on the road, especially large trucks and trailers, are often great enough to cause the drum to shift no matter how tight the lug nuts.
Slippage of the drum tends to cause the wheel to be off center and out of balance. Even if the tires and wheels are initially balanced after being mounted, the drum may shift or slip during use so that they are soon out of balance. When the tire and wheel is out of balance, vibration and premature tire wear are usually the result. In extreme cases, handling of the vehicle can be impaired and severe tire damage may result, increasing the chances of a dangerous blow out, tread loss or flat.
As can be seen, improvements in such wheel mounting assemblies are needed.
A wheel mounting assembly is provided. The wheel mounting assembly includes a hub having at least one bolt extending therefrom. A drum having an aperture receives the at least one bolt. The aperture has a width that is substantially greater than that of the lug or bolt to thus define an area of space between the bolt and the sides of the aperture. The assembly also includes a spacing insert having a body with a bore for closely receiving the at least one bolt. The body is configured to be closely received within the aperture of the drum so that the area of space is generally filled by the spacing insert when positioned therein.
A device for preventing relative movement of a drum and hub of a wheel mounting assembly is also provided, wherein the hub has at least one bolt extending therefrom which extends through an aperture of the drum and a bolt hole of the wheel when the drum and wheel are mounted thereon, and wherein the aperture has a width that is substantially greater than that of the at least one bolt thus defining an area of space between the bolt and the sides of the aperture. The device includes a spacing insert having a body with a bore for closely receiving the at least one bolt. The body is configured to be closely received within the aperture of the drum so that the area of space is generally filled by the spacing insert when positioned therein to thereby restrict relative movement of the bolt within the aperture.
A method of preventing relative movement of a drum and hub of a vehicle wheel mounting assembly is further provided, wherein the hub has at least one bolt extending therefrom over which the drum is mounted, and wherein the drum has an aperture with a width that is substantially greater than that of the at least one bolt to thus define an area of space between the bolt and the sides of the aperture. The method includes providing a spacing insert formed from a body having a bore for closely receiving the at least one bolt. The body is configured to be closely received within the aperture of the drum. The body of the spacing insert is inserted into the aperture so that the area of space is generally filled by the body when positioned therein to thereby prevent relative movement of the bolt within the aperture.
In certain embodiments, the spacing insert may have a sleeve portion extending from the body. The sleeve portion has a bore for closely receiving the at least one bolt and is configured to be closely received within the bolt hole of a wheel of the assembly.